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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.handler.codec.compression;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;

import java.util.List;

import static io.netty.handler.codec.compression.Bzip2Constants.BASE_BLOCK_SIZE;
import static io.netty.handler.codec.compression.Bzip2Constants.BLOCK_HEADER_MAGIC_1;
import static io.netty.handler.codec.compression.Bzip2Constants.BLOCK_HEADER_MAGIC_2;
import static io.netty.handler.codec.compression.Bzip2Constants.END_OF_STREAM_MAGIC_1;
import static io.netty.handler.codec.compression.Bzip2Constants.END_OF_STREAM_MAGIC_2;
import static io.netty.handler.codec.compression.Bzip2Constants.HUFFMAN_MAXIMUM_TABLES;
import static io.netty.handler.codec.compression.Bzip2Constants.HUFFMAN_MAX_ALPHABET_SIZE;
import static io.netty.handler.codec.compression.Bzip2Constants.HUFFMAN_MINIMUM_TABLES;
import static io.netty.handler.codec.compression.Bzip2Constants.HUFFMAN_SELECTOR_LIST_MAX_LENGTH;
import static io.netty.handler.codec.compression.Bzip2Constants.HUFFMAN_SYMBOL_RANGE_SIZE;
import static io.netty.handler.codec.compression.Bzip2Constants.MAGIC_NUMBER;
import static io.netty.handler.codec.compression.Bzip2Constants.MAX_BLOCK_SIZE;
import static io.netty.handler.codec.compression.Bzip2Constants.MAX_SELECTORS;
import static io.netty.handler.codec.compression.Bzip2Constants.MIN_BLOCK_SIZE;

/**
 * Uncompresses a {@link ByteBuf} encoded with the Bzip2 format.
 *
 * See Bzip2.
 */
public class Bzip2Decoder extends ByteToMessageDecoder {
    /**
     * Current state of stream.
     */
    private enum State {
        INIT,
        INIT_BLOCK,
        INIT_BLOCK_PARAMS,
        RECEIVE_HUFFMAN_USED_MAP,
        RECEIVE_HUFFMAN_USED_BITMAPS,
        RECEIVE_SELECTORS_NUMBER,
        RECEIVE_SELECTORS,
        RECEIVE_HUFFMAN_LENGTH,
        DECODE_HUFFMAN_DATA,
        EOF
    }
    private State currentState = State.INIT;

    /**
     * A reader that provides bit-level reads.
     */
    private final Bzip2BitReader reader = new Bzip2BitReader();

    /**
     * The decompressor for the current block.
     */
    private Bzip2BlockDecompressor blockDecompressor;

    /**
     * Bzip2 Huffman coding stage.
     */
    private Bzip2HuffmanStageDecoder huffmanStageDecoder;

    /**
     * Always: in the range 0 .. 9. The current block size is 100000 * this number.
     */
    private int blockSize;

    /**
     * The CRC of the current block as read from the block header.
     */
    private int blockCRC;

    /**
     * The merged CRC of all blocks decompressed so far.
     */
    private int streamCRC;

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List out) throws Exception {
        if (!in.isReadable()) {
            return;
        }

        final Bzip2BitReader reader = this.reader;
        reader.setByteBuf(in);

        for (;;) {
            switch (currentState) {
            case INIT:
                if (in.readableBytes() < 4) {
                    return;
                }
                int magicNumber = in.readUnsignedMedium();
                if (magicNumber != MAGIC_NUMBER) {
                    throw new DecompressionException("Unexpected stream identifier contents. Mismatched bzip2 " +
                            "protocol version?");
                }
                int blockSize = in.readByte() - '0';
                if (blockSize < MIN_BLOCK_SIZE || blockSize > MAX_BLOCK_SIZE) {
                    throw new DecompressionException("block size is invalid");
                }
                this.blockSize = blockSize * BASE_BLOCK_SIZE;

                streamCRC = 0;
                currentState = State.INIT_BLOCK;
                 // fall through
            case INIT_BLOCK:
                if (!reader.hasReadableBytes(10)) {
                    return;
                }
                // Get the block magic bytes.
                final int magic1 = reader.readBits(24);
                final int magic2 = reader.readBits(24);
                if (magic1 == END_OF_STREAM_MAGIC_1 && magic2 == END_OF_STREAM_MAGIC_2) {
                    // End of stream was reached. Check the combined CRC.
                    final int storedCombinedCRC = reader.readInt();
                    if (storedCombinedCRC != streamCRC) {
                        throw new DecompressionException("stream CRC error");
                    }
                    currentState = State.EOF;
                    break;
                }
                if (magic1 != BLOCK_HEADER_MAGIC_1 || magic2 != BLOCK_HEADER_MAGIC_2) {
                    throw new DecompressionException("bad block header");
                }
                blockCRC = reader.readInt();
                currentState = State.INIT_BLOCK_PARAMS;
                // fall through
            case INIT_BLOCK_PARAMS:
                if (!reader.hasReadableBits(25)) {
                    return;
                }
                final boolean blockRandomised = reader.readBoolean();
                final int bwtStartPointer = reader.readBits(24);

                blockDecompressor = new Bzip2BlockDecompressor(this.blockSize, blockCRC,
                                                                blockRandomised, bwtStartPointer, reader);
                currentState = State.RECEIVE_HUFFMAN_USED_MAP;
                // fall through
            case RECEIVE_HUFFMAN_USED_MAP:
                if (!reader.hasReadableBits(16)) {
                    return;
                }
                blockDecompressor.huffmanInUse16 = reader.readBits(16);
                currentState = State.RECEIVE_HUFFMAN_USED_BITMAPS;
                // fall through
            case RECEIVE_HUFFMAN_USED_BITMAPS:
                Bzip2BlockDecompressor blockDecompressor = this.blockDecompressor;
                final int inUse16 = blockDecompressor.huffmanInUse16;
                final int bitNumber = Integer.bitCount(inUse16);
                final byte[] huffmanSymbolMap = blockDecompressor.huffmanSymbolMap;

                if (!reader.hasReadableBits(bitNumber * HUFFMAN_SYMBOL_RANGE_SIZE + 3)) {
                    return;
                }

                int huffmanSymbolCount = 0;
                if (bitNumber > 0) {
                    for (int i = 0; i < 16; i++) {
                        if ((inUse16 & 1 << 15 >>> i) != 0) {
                            for (int j = 0, k = i << 4; j < HUFFMAN_SYMBOL_RANGE_SIZE; j++, k++) {
                                if (reader.readBoolean()) {
                                    huffmanSymbolMap[huffmanSymbolCount++] = (byte) k;
                                }
                            }
                        }
                    }
                }
                blockDecompressor.huffmanEndOfBlockSymbol = huffmanSymbolCount + 1;

                int totalTables = reader.readBits(3);
                if (totalTables < HUFFMAN_MINIMUM_TABLES || totalTables > HUFFMAN_MAXIMUM_TABLES) {
                    throw new DecompressionException("incorrect huffman groups number");
                }
                int alphaSize = huffmanSymbolCount + 2;
                if (alphaSize > HUFFMAN_MAX_ALPHABET_SIZE) {
                    throw new DecompressionException("incorrect alphabet size");
                }
                huffmanStageDecoder = new Bzip2HuffmanStageDecoder(reader, totalTables, alphaSize);
                currentState = State.RECEIVE_SELECTORS_NUMBER;
                // fall through
            case RECEIVE_SELECTORS_NUMBER:
                if (!reader.hasReadableBits(15)) {
                    return;
                }
                int totalSelectors = reader.readBits(15);
                if (totalSelectors < 1 || totalSelectors > MAX_SELECTORS) {
                    throw new DecompressionException("incorrect selectors number");
                }
                huffmanStageDecoder.selectors = new byte[totalSelectors];

                currentState = State.RECEIVE_SELECTORS;
                // fall through
            case RECEIVE_SELECTORS:
                Bzip2HuffmanStageDecoder huffmanStageDecoder = this.huffmanStageDecoder;
                byte[] selectors = huffmanStageDecoder.selectors;
                totalSelectors = selectors.length;
                final Bzip2MoveToFrontTable tableMtf = huffmanStageDecoder.tableMTF;

                int currSelector;
                // Get zero-terminated bit runs (0..62) of MTF'ed Huffman table. length = 1..6
                for (currSelector = huffmanStageDecoder.currentSelector;
                            currSelector < totalSelectors; currSelector++) {
                    if (!reader.hasReadableBits(HUFFMAN_SELECTOR_LIST_MAX_LENGTH)) {
                        // Save state if end of current ByteBuf was reached
                        huffmanStageDecoder.currentSelector = currSelector;
                        return;
                    }
                    int index = 0;
                    while (reader.readBoolean()) {
                        index++;
                    }
                    selectors[currSelector] = tableMtf.indexToFront(index);
                }

                currentState = State.RECEIVE_HUFFMAN_LENGTH;
                // fall through
            case RECEIVE_HUFFMAN_LENGTH:
                huffmanStageDecoder = this.huffmanStageDecoder;
                totalTables = huffmanStageDecoder.totalTables;
                final byte[][] codeLength = huffmanStageDecoder.tableCodeLengths;
                alphaSize = huffmanStageDecoder.alphabetSize;

                /* Now the coding tables */
                int currGroup;
                int currLength = huffmanStageDecoder.currentLength;
                int currAlpha = 0;
                boolean modifyLength = huffmanStageDecoder.modifyLength;
                boolean saveStateAndReturn = false;
                loop: for (currGroup = huffmanStageDecoder.currentGroup; currGroup < totalTables; currGroup++) {
                    // start_huffman_length
                    if (!reader.hasReadableBits(5)) {
                        saveStateAndReturn = true;
                        break;
                    }
                    if (currLength < 0) {
                        currLength = reader.readBits(5);
                    }
                    for (currAlpha = huffmanStageDecoder.currentAlpha; currAlpha < alphaSize; currAlpha++) {
                        // delta_bit_length: 1..40
                        if (!reader.isReadable()) {
                            saveStateAndReturn = true;
                            break loop;
                        }
                        while (modifyLength || reader.readBoolean()) {  // 0=>next symbol; 1=>alter length
                            if (!reader.isReadable()) {
                                modifyLength = true;
                                saveStateAndReturn = true;
                                break loop;
                            }
                            // 1=>decrement length;  0=>increment length
                            currLength += reader.readBoolean() ? -1 : 1;
                            modifyLength = false;
                            if (!reader.isReadable()) {
                                saveStateAndReturn = true;
                                break loop;
                            }
                        }
                        codeLength[currGroup][currAlpha] = (byte) currLength;
                    }
                    currLength = -1;
                    currAlpha = huffmanStageDecoder.currentAlpha = 0;
                    modifyLength = false;
                }
                if (saveStateAndReturn) {
                    // Save state if end of current ByteBuf was reached
                    huffmanStageDecoder.currentGroup = currGroup;
                    huffmanStageDecoder.currentLength = currLength;
                    huffmanStageDecoder.currentAlpha = currAlpha;
                    huffmanStageDecoder.modifyLength = modifyLength;
                    return;
                }

                // Finally create the Huffman tables
                huffmanStageDecoder.createHuffmanDecodingTables();
                currentState = State.DECODE_HUFFMAN_DATA;
                // fall through
            case DECODE_HUFFMAN_DATA:
                blockDecompressor = this.blockDecompressor;
                final int oldReaderIndex = in.readerIndex();
                final boolean decoded = blockDecompressor.decodeHuffmanData(this.huffmanStageDecoder);
                if (!decoded) {
                    return;
                }
                // It used to avoid "Bzip2Decoder.decode() did not read anything but decoded a message" exception.
                // Because previous operation may read only a few bits from Bzip2BitReader.bitBuffer and
                // don't read incoming ByteBuf.
                if (in.readerIndex() == oldReaderIndex && in.isReadable()) {
                    reader.refill();
                }

                final int blockLength = blockDecompressor.blockLength();
                ByteBuf uncompressed = ctx.alloc().buffer(blockLength);
                try {
                    int uncByte;
                    while ((uncByte = blockDecompressor.read()) >= 0) {
                        uncompressed.writeByte(uncByte);
                    }
                    // We did read all the data, lets reset the state and do the CRC check.
                    currentState = State.INIT_BLOCK;
                    int currentBlockCRC = blockDecompressor.checkCRC();
                    streamCRC = (streamCRC << 1 | streamCRC >>> 31) ^ currentBlockCRC;

                    out.add(uncompressed);
                    uncompressed = null;
                } finally {
                    if (uncompressed != null) {
                        uncompressed.release();
                    }
                }
                // Return here so the ByteBuf that was put in the List will be forwarded to the user and so can be
                // released as soon as possible.
                return;
            case EOF:
                in.skipBytes(in.readableBytes());
                return;
            default:
                throw new IllegalStateException();
            }
        }
    }

    /**
     * Returns {@code true} if and only if the end of the compressed stream
     * has been reached.
     */
    public boolean isClosed() {
        return currentState == State.EOF;
    }
}
    

    

    

            

    

            



    
    






    
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